Upgrade rust/crates/cexpr to 0.6.0 am: 417a5cbdb1 am: 6e902fa055

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/cexpr/+/2137713

Change-Id: I6d255d34df8d6a466a90c623ade72f50717960d0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>